Liquid-solid Equilibria in Quinary System Na+, K+, Mg2+//Cl-, NO3--H2O at 25 °C

The solubilities of the quinary system Na+, Mg2+//Cl-, NO3--H2O and its two quaternary subsystems, Na+, K+, Mg2+//NO3--H2O and K+, Mg2+/Cl-, NO3--H2O, were studied by isothermal method at 25 degrees C and their phase diagrams were plotted. In the equilibrium phase diagram of quaternary system Na+, K+, Mg2+//NO3--H2O, there are one invariant point, three univariant curves and three regions of crystallization with one salt: NaNO3, KNO3 and Mg(NO3)(2)center dot 6H(2)O. In the equilibrium phase diagram of quaternary system K+, Mg2+//Cl-, NO3--H2O, there are three invariant points, seven univariant curves and five regions of crystallization with one salt: KNO3, KCl, Mg(NO3)(2)center dot 6H(2)O, MgCl2 center dot 6H(2)O and KCl center dot MgCl2 center dot 6H(2)O. In the equilibrium phase diagram of the quinary system Na+, K+, Mg2+//Cl-, NO3--H2O, there are four invariant points, and seven regions of crystallization with one salt: NaCl, KCl, NaNO3, KCl center dot MgCl2 center dot 6H(2)O, KNO3, MgCl2 center dot 6H(2)O and Mg(NO3)(2)center dot 6H(2)O.